Lift-trucks are often used in order picking operations where an operator manually collects goods from the shelves in warehouse and places the goods on the load engagement means of the lift-truck. A general problem associated with order picking is that the working height of the operator changes as the goods accumulate on the load engagement means, or are removed there from. To find an ergonomically correct working position, the operator is therefore forced to repeatedly raise or lower the load engagement means of the lift-truck. This is time consuming and reduces the efficiency of the order picking operation.
Attempts have been made to address this problem. DE 20 2012 004 038 U1 describes a forklift truck comprising a load carrier which is connected by a chain/pulley arrangement to a telescopic lifting mast such that the load carrier is raised on the mast when the telescopic mast is extended. A laser sensor is attached to the top of the telescopic mast to measure the distance from the sensor to the goods on a load carrier. The laser sensor is connected to a control unit which determines changes in the distance between the sensor and the goods on the load carrier and adjusts the height of the load carrier accordingly. However, since the load carrier and the telescopic mast are movable relative each other, the distance between the load carrier and the laser sensor may change when the height of the load carrier is adjusted. This may in turn cause inaccuracies in the determination of the level of the goods on the load carrier.
As a consequence, the automated height adjustment of the load carrier is rather complicated and dependent on several parameters, such as desired working height and actual load carrier height, which are feed to the control unit. Determination of these parameters further requires multiple distance measurements in different directions and that the control unit performs various calculations.
Thus, it is an object of the present disclosure to provide an improved lift-truck which solves or at least mitigates one of the problems of the prior-art. In particular, it is an object of the present disclosure to provide a lift-truck which provides for simple and reliable automatic adjustment of the load engagement means in dependency of changes of the level of goods thereon. In addition it is an object of the present disclosure to provide an inexpensive lift-truck which provides for simple and reliable automated adjustment of the load engagement means.